Valve-gear.



R;G.GRAHAM.

VALVE GEAR.l

APPLICATION FILED IULYII. I9l6. 1,21 9,549B Patented Mar. 20, 1917.,

l 4 SHEETS-SHEET L R. G. GRAHAM.

VALVE GEAR.

APPLICATION FILED IULYH. 1916. 1 ,21 9,549. Patented Mar. 20, 1917.

4 SHEETS-SHEET Z- l a.. Q

lq i I O I A# i l i f A 1\ b N nii/ENT DR.. /lou //m/aM/L,

R. G. GRAHAM.

VALVE GEAR.

APPLICATION FILED IIILY I1. I9Is.

1,21 9,549. i Patented Mar. 20, 1917.

4 SHEETS-SHEET 3.

IN/'ENT DR ,RI G. GRAHAM.

VALVE GEAR.

APPLICATION FILED IuLYII. I9I6.

1 ,2l 9,549 Patented Mar. 20, 1917.

4 SHEETS-SHE ESSURE HIGH PRESSURE INVENTEFL Maag/.

LOW

ROSS Gr. GRAHAM, OF SWANTON, OHIO, ASSIGNOR T0 THE PILLIOD COMPANY, OFSWANTON', OHIO, A CORPORATION OF OHIO.

VALVE-GEAR.

Specification of Letters Patent.

Patented Mar. 20, 1917.

Application tiled July 17, 1916. Serial No. 109,751.

To all whom t may concern.'

Be it known that I, Ross G. GRAHAM, a citizen of ther United States, anda resident of Swanton, in the county of Fulton and State of Ohio, haveinvented a certain new and useful Valve-Gear; and I do hereby declarethe following to be a full, clear, and exact description of theinvention, vsuch as will enable others skilled in the art to which itappertains to make and use the same, reference being'had to theaccompanying draw-4 ings, and to the characters of reference markedthereon, which form a part of this specification. i

This inventon relates to locomotives,y and particularly to valve gearsfor use on loco,

motives of the compound Mallet type, but is not restricted to use inconnection with such type of locomotives.

It has been found in practice that for etlilciency ,and ideal runningand operating conditions with engines of the type described it isdesirable for starting or slow running to admit steam in such proportionto the high and low pressure cylinders that the high pressure cylinderis then the stronger, and for fast running to admit steam to thecylinders in such proportion thatI thevlow pres-` sure. cylinder is thenthe stronger. In practice means for obtaining these reverse'or twfconditions hasnot been present-in a single locomotive, so that alocomotive adapted for slow runnin and heavy pulling was not adapted forast running, and viceversa.

The object of my invention is to combine in a single mechanism means forobtaining these two ideal running conditions so that a locomotiveequipped therewith will be adapted for both slow and Afast running,thereby enhancing the eiliciency and materiallybroadening the rangel ofuse of locomotlves of the character described.

-The invention is fully described in the following specification, andwhile, in its .broader aspect, it is capable of embodiment in numerousforms, a preferred embodiment thereof isillustrated in the accompanyingdrawings in connection with a valve gear of the Baker type, in whichdrawings- Figure 1 is a side elevation of a Mallet type of engineembodying my invention. Fig. 2 is a side elevation of the front truckand low pressure cylinder with the associated valve gear. Fig. 3 is aside elevation of the rear truck and high pressure cylinder with thevalve gear associated therewith. Fig. 4 is an enlarged longitudinalsectional View of a Valve gear of the Baker type with parts broken away.Figs. 5 and 6 are different cross-sections thereof with parts brokenaway. Fig. 7 is a perspective view of a portion of the connecting meansbetween the front and rear gears. Fig. 8 is a diagrammatical View of thefront and rear valve gears and the connection therebetween illustratingthe invention, and Figs. 9 and 10 are charts produced by the highpressure and low pressure engines.

' Referring to the drawings, A and B designate the respective 'high andlow pressure cylinders on one side of the locomotive of the Mallet type,and C and D the valve gears for the respective cylinders, which gearsare connected together to operate in unison.

The valve -gear C is carried by agear frame 1 suitably mounted at a sideof the locomotive, as on the guide yoke 2 and embodies a reverse-yoke 3,which isof substantially inverted U-form, and has its legs journaled inthe respective sides of the frame 1, as at 4. A second yoke 5 issuspended within the reverse-yoke 3, having its leg ends provided withtrunnions which are -journaled in bearings 6 provided in the respectivelegs of the reverse-yoke near their inner ends. A gear connecting rod 7in the form of a lever, is pivotally carried intermediate its ends invertical position by the lower end of the yoke, as at'8, and has itsupperrend pivoted to the horizontal arm of a bell-crank lever 9, whichlever is fulcrumed at 10 to the gear frame 1 between the sides thereof.,A The -The lower end of the lever 15 is pivoted to a union link 17,which is in turn pivotally carried by the piston rod cross-head` 18 ofthe cylinder A (FigsQ3 and 4).

Itwill be noted that the union link 17 is connected directly to thecross-head 18 instead of'to an arm carried by and depending fromthe,crosshead, as has heretofore been the practice. This not onlyeliminates one part but quite materially lightens the crosshead, whichis an important feature.

The forward valve gear D is approximately the same as the gear C eXceptthat if one is reversed with respect to the other. In the gear D, 1'designates the gear frame; 3' the reverse-yoke pivoted to the frame, lasat 4'; 5' the second yoke pivoted to the reverse-yoke, as at 6'; 7 thegear connecting rod pivoted to the yoke 5', as at 8' 9' vthe bell-crankpivoted to the frame 1', as at 10'.; 11' the eccentric rod; 14 thevalve-rod; 15' the combination lever; 16' the valvel stem cross-head,and 17 the union link.

With the exception of the manner -of connecting the combination levers15, 15' to the cross-heads 18, 18', the valve gears C and D illustratedare the well known Baker type and the construction and operation thereofneed not, therefore, be more specifically described. i

Intermediate the two trucks of the locomotive are mounted a pair ofparallel rockshafts 19 andi20, which extend from one side to the otherof the locomotive transversely thereof. These shafts are caused to lhavelike rocking movements in unison by reason of av link 21 havinguniversall joint connection at its ends with respective arms 22 and 23fixedly risin in parallel relation from the shafts (Fig. 7%. A verticalarm l24 at each end of the shaft 19 is connected at its free end by areach-rod 25 to the upper end ofthe reverse-yoke 3-of the respectivegear C.- A similar arm 26 at each end of the shaft 20 is connected by areach-rod 27 to the upper end of the reverse-yoke 3 of the respectlvegear D. The purpose of providing the two shafts 19 and 20 and theuniverysal connection therebetween is to allow for the relativey turningmovements of the two trucks of the locomotive as it takes curves.

'If it was not for this the arms might all be mounted on one shaft, asboth shafts are intended to have the same movements.

It is to be understood that the connection between the front and rearvalve gears is the same as heretoforeemployed in connection withcompound engines of the vMallet type employing valve gears of the Bakertype,

except that the arms 26 on thev shaft 20 are inclined forward atapproximately a 45 angle to the'arms 24 instead of being parallel 1 orsubstantially parallel therewith, as has heretofore been the custom, andit is in this slight difference in construction that the primary featureof the invention resides, as will I be hereinafter more fully described.a

The means illustrated, in the present 1nstance, for controlling themovements of the shafts 19 and 2O and the reverse-yokes of therespective valve gears comprises a rod 28, which is connected at one endto an arm 29 rising from the shaft 19 and has its other end connected toa piston, not shown, within a control cylinder 30 (Figs. 1 and 7). It isevident that the admission of fluid under pressure to the cylinder 30 tocontrol the movements of the rod 28 is under control of' the engineerwithin the locomotive cab, as is well understood in the art.

Referring to Fig. 8, a and a' designate 'able to reverse this conditionso that the 'high pressure engine has the` longer cut- These reversedoff at full gear position. conditions are obtained by inclining the arms26 on the shaft 20 at approximately an 'angle of 45 to the verticallydisposed arms 24 on the shaft 19 and making the arms 26 slightly longerthan the arms 24. By this arrangement it will be Anoted in Fig. 8 thatwhen the reverse-yoke 3 is in vits full-gear position the reverse-yoke3' ofthe forward valve gear D will be in its full gear' position af; andalso that when the reverse-yoke 3 is moved to its mid-gear position bthe reverseyoke 3' will only have moved a portion of the distance'to itsmid-gear position b. It is apparent that when the reverse-yokes are inthis position the high pressure engine will have the longer cut-oil' andwill therefore be the stronger of the two. This is illustratedl by theellipse diagrams shown in Figs. 9 and 10, which are for the high and lowpressure engines, respectively.v In these diagrams thev outerellipses ofthe respective engines were taken when lthe valve gears were set forstarting or; slow running, and the inner ellipses ofthe respective vengines were taken when the valve gears were hookednp for high speedrunning. In `the high pressure diagram (Fig. 9) the first vertical line,from left to right, indicates the preadmission and cut-off points, thesecond line indicates the release and closure points for a forwardstroke of the'piston, and the last two lines indicate the release andlclosure points and the preadniiion and cut-oit points for the backstroke of the piston. The low pressure diagram (Fig. l0) is the same inits reading as the high pressure diagram except that the forward stroketakes place at the right instead of at the left of the center verticalline. From the outer ellipses it will be noted that in starting, or forslow running, steam is admitted to the high pressure engineapproximately between the points c and c, the cutofi' occurring at c,while in the low pressure engine steam is admitted approximately betweenthe points d and d', the cutoff occurring atv d', thus showing that thehigh pressure engine, under such condition, has the longer cut-off ofthe two and is therefore the stronger. The inner ellipses of the twocharts show that when the valve gears are hooked up for high speedrunning the cut-oil of the high pressure engine takes place atapproximately the point e and that the cut-ofi? on the low pressureengine takes place at approximately the point f, thus showing that thelow pressure engine carries steam the longest and is the stronger underhigh speed running conditions.

This arrangement does not in any way sacrifice the reversing orbacking-up motion, as will be apparent from the diagram. The purpose ofmaking the arms 26 longer than the arms 24 is to lengthen the arc ofmovement of the point of connection of the reach-rods 27 with the arms26 and to effect a corresponding increase of the horizontal movement ofsuch points of connection when the arms 26 are swung rearward from fullrunning position.

It is apparent from the above that by ad-I vancing the arc of the lowpressure reverse shaft arms 26 the rate of hooking up of the lowpressure engine with respect to the high is retarded, giving for astarting condition considerably longer cut-oii at full gear onthe highpressure engine than on the low, with a reversed condition for thehigher speeds or running position, in which the low pressure enginecarries steam considerably longer than the high pressure. This improvesthe steam distribution by relieving the high pressure engine of backpressure at high speeds ranging from 10 to 5() miles an hour, and at thesame time gives an ideal distribution of steam for starting purposes. Ifthe valves are set to produce the same cut-offs on both engines at allreverse lever positions it is impossible on account of back pressure toobtain a speed of over l0 miles per hour.

The chart diagrams in Figs. 9 and 10 are shown in reversed positions dueto the high pressure engine havingan inside admission piston valve andthe low pressure engine having an outside admission slide valve.

I wish it understood that my invention is not limited to any specificconstruction,

arrangement or form of the parts o1 to use in connection with anyparticular type of valve gear, as it is capable of numerousmodifications and uses in different connections without departing fromthe spirit of the invention.

Having thus described my invention, what I claim as new, and 'desire tosecure by Letters Patent, is-

1. The combination with a pair of valve gears, of a connecting mechanismtherebetween including a pair of rocker arms one inclined with respectto the other and connected to rock in unison, and separate meansconnecting said arms to respective gears.

2. The combination with a pair of valve gears, of aconnecting mechanismtherebetween including a pair of relatively angled rocker arms,pivotally-jointed connection between said arms to cause them to rock inunison, and separate means connecting said arms to respective gears.

3. The combination with a pair of valve gears, each having a reversemember, of-a pair of connected relatively angled rocker arms adapted torock in unison, and, separate means connecting said arms to the reversemembers of respective gears.

4. The combination with a pair of valve gears, each having a reversemember, of a pair of connected rocker arms, one lat approximately a 450angle to the other, adapted to rock in unison, and separate meansconnecting said arms to the reverse members of respective gears.

5. In a locomotive having connected high and low pressure engines, thecombination with a valve gear for each engine, of mechanism connected toeach of said gears and having a plurality of relatively angled rockerarms, the angled arms of the mechanism causing it when operated toimpart different predetermined `movements 'to said gears in unison tovary the reiative periods of cut-ofi' of the admission valves of theengines.

6. The combination with a pair of valve gears, each having a reversemember, of a single means connecting said members, and having aplurality of relatively angled rocker arms for causing differentadjustments to be imparted to said members when said means is moved.

7. In a locomotive having connected high and low pressure engines, thecombination with a valve gear for each engine, of mechanism connected toeach of said gears and operable to simultaneously adjust the same, saidmechanism having a pair of relatively angled arms connected torespective gears and adapted to cause the movement communicated to onegear by a movement of said mechanism to differ from that of the othergear, and means for' moving said mechanism.

8. The combination with a pair of valve gears arranged one in advance ofthe other, of a connecting mechanism therebetween ineluding a pair ofrocker arms, one inclined relative to the other and connected to rock inunison, and separate means connecting said arms to respective gearswhereby one gear is caused to have a'diferently'timed valve cut-off fromthe other` when the mechanism is moved. 10

In testimony whereof I have hereunto signed my name to thisspeciication.

ROSS G. GRAHAM.

